Sleep Calculator
Sleep in full cycles of about 90 minutes, and it takes about 15 minutes to fall asleep. Pick a wake-up time for bedtimes, or a bedtime for wake-up times.
| Time | Cycles | Hours of sleep |
|---|
How to use Sleep Calculator
- Choose whether you want to wake up at a time or go to bed at a time.
- Enter the time and read the options.
What is a sleep cycle?
Sleep moves through stages in cycles of about 90 minutes. Waking at the end of a cycle often feels easier.
Is this medical advice?
No. Everyone sleeps differently, so use this as a guide.